Comparative analysis of the anatomy of two populations of red-root amaranth (Amaranthus retroflexus L.)

Abstract

SUMMARYThe anatomy of stems and leaves of two populations of the weed species Amaranthus retroflexus L. (red-root amaranth) (pop. AMARE 1 having green stems covered in sparse hairs and pop. AMARE 2 with green but notably dense stem hairs) was analysed in order better to understand the uptake and translocation of herbicides that could be indicative of the species' evolving resistance to herbicides. Samples of the two populations (AMARE 1 and AMARE 2 ) were collected from arable land of the Institute of Maize Research at Zemun Polje in 2006. Sampling was performed at the stage of full vegetative growth of plants. Permanent microscoping preparations were made to measure and analyze elements of the anatomy of stems (stem epidermis, cortex, collenchyma, central cylinder and diameter) and leaves (leaf epidermis upper surface and underside, mesophyll, leaf thickness and bundle sheath thickness).Both analysed populations of A. retroflexus, morphologically characterized by different density of stem hairiness, were found to have a typical structure of herbaceous dicots. The stem had three distinctive zones: epidermis, cortex and central cylinder. Amaranth leaves have dorsoventral structure, i.e. their upper surface and underside can be differentiated. The results indicated high and very high significance of differences found in stem anatomy between the two analysed populations, while leaf anatomy was not found to display significant differences other than in mesophyll thickness.

Assessment of genetic relatedness of the two Amaranthus retroflexus populations by protein and random amplified polymorphic DNA (RAPD) markers

“…In the Maize Research Institute field, two biotypes of A. retroflexus is presented; population 1 having stem covered in sparse hairs and population 2 with notable dense stem hairs. The results of previous study of morphological traits of those two populations (Vrbnicanin et al, 2009) indicate that apart from differences in hairiness, they differ also in the anatomy of stem (stem diameter, epidermis thickness, cortex diameter, collenchymas thickness, and central cylinder diameter) as well as leaf anatomy (mesophyll thickness). According to same authors, such differences between populations provide basis for better understanding of plant reaction in terms of herbicide uptake and translocation that are potentially connected to an evolution of resistance to herbicides in the locality Zemun Polje, Serbia.…”

Taxonomical study of Caroxylon jordanicola (Eig) Akhani & Roalson (Amaranthaceae) in Al-Tar Caves, Karbala, Iraq

“…This species possesses a cortex with two zones, the first 1-2 layered was thin, oblong cells, the chlorenchyma cells found outside the cortex under the epidermis that capable for photosynthesis, Also this layer in stem of many plants. The cortex thickness was also recorded and measured, which was 210 μm [16,17].This species lack crystals. After, we have endodermis which consist of single layer of round, square and rectangular cells with thick walls, followed by pericycle, which consist of one layer thin walled cells.…”